Hairpin winding electric machine

Abstract

An electric machine includes a stator core and hairpin windings. The stator core defines slots that are circumferentially arranged between an inner diameter and an outer diameter of the stator core. Each slot has a plurality of pin positions that is arranged in a direction that extends from the inner diameter of the stator core toward the outer diameter of the stator core. The hairpin windings have a plurality of electrical paths of interconnected hairpins disposed within the slots. Each of the plurality of electrical paths of interconnected hairpins have a plurality of typical hairpins and a plurality of atypical hairpins. Each typical hairpin has first and second opposing inwardly extending twist portions. Each atypical hairpin has a third inwardly extending twist portion and an outwardly extending twist portion disposed on an opposing end of the atypical hairpin relative to the third inwardly extending twist portion.

What is claimed is: 
     
       1. An electric machine comprising:
 a stator core defining slots that are circumferentially arranged between an inner diameter and an outer diameter of the stator core, each slot having a plurality of pin positions that is arranged in a direction that extends from the inner diameter of the stator core toward the outer diameter of the stator core; and 
 hairpin windings having a plurality of electrical paths of interconnected hairpins disposed within the slots, each of the plurality of electrical paths of interconnected hairpins having a plurality of typical hairpins and a plurality of atypical hairpins, wherein (i) each typical hairpin has a crown pitch of eight, nine, or ten, slots and opposing inwardly extending twist pitches along each end of the typical hairpin of four and one half slots, (ii) each atypical hairpin has an inwardly extending twist pitch and an outwardly extending twist pitch on opposing respective ends of the atypical hairpin, (iii) a subset of hairpins forms terminal lead connections along an inner diameter or an outer diameter of the hairpin windings, and (iv) a portion of the subset of hairpins are atypical hairpins. 
 
     
     
       2. The electric machine of  claim 1 , wherein a remainder of the hairpins other than the subset of hairpins along the inner and outer diameters of the hairpin windings are each atypical hairpins. 
     
     
       3. The electric machine of  claim 1 , wherein (i) the hairpin windings for three electrical phases and (ii) each electrical phase is comprised of three of the plurality of electrical paths of interconnected hairpins. 
     
     
       4. The electric machine of  claim 3 , wherein the three electrical paths of interconnected hairpins of each electrical phase are arranged in parallel relative to each other. 
     
     
       5. The electric machine of  claim 3 , wherein each electrical phase has six poles, and wherein each pole is comprised of a portion of the interconnected hairpins that occupy three consecutive slots. 
     
     
       6. The electric machine of  claim 1 , wherein a subset of hairpins disposed in a middle layer between an inner diameter and an outer diameter of the hairpin windings are arranged in groups of three, (ii) each hairpin of each group of three is from a different electrical path of the plurality of electrical paths, and (hit) each group of three includes one hairpin having a crown pitch of eight, one hairpin having a crown pitch of nine, and one hairpin having a crown pitch of ten. 
     
     
       7. An electric machine comprising:
 a stator core defining slots that are circumferentially arranged betw een an inner diameter and an outer diameter of the stator core, each slot having a plurality of pin positions that is arranged in a direction that extends from the inner diameter of the stator core toward the outer diameter of the stator core; and 
 hairpin windings having a plurality of electrical paths of interconnected hairpins disposed within the slots, each of the plurality of electrical paths of interconnected hairpins having a plurality of typical hairpins and a plurality of atypical hairpins, wherein (i) each typical hairpin has first and second opposing inwardly extending twist portions, (ii) each atypical hairpin has a third inwardly extending twist portion and an outwardly extending twist portion disposed on an opposing end of the atypical hairpin relative to the third inwardly extending twist portion, (ii) each of the atypical hairpins is disposed along an inner diameter or an outer diameter of the hairpin windings, (iv) each atypical hairpin has a crown that spans nine slots, and (v) the third inwardly extending twist portion of each atypical hairpin spans four and one half slots. 
 
     
     
       8. The electric machine of  claim 7 , wherein each typical hairpin has a crown that spans eight, nine, or ten slots. 
     
     
       9. The electric machine of  claim 8 , wherein the first and second opposing inwardly extending twist portions of each typical hairpin spans four and one half slots. 
     
     
       10. The electric machine of  claim 7 , wherein a subset of hairpins disposed in a middle layer between an inner diameter and an outer diameter of the hairpin windings are arranged in groups of three, (ii) each hairpin of each group of three is from a different electrical path of the plurality of electrical paths, and (iii) each group of three includes one hairpin having a crown pitch of eight, one hairpin having a crown pitch of nine, and one hairpin having a crown pitch of ten. 
     
     
       11. The electric machine of  claim 7 , wherein a subset of hairpins forms terminal lead connections along an inner diameter or an outer diameter of the hairpin windings. 
     
     
       12. The electric machine of  claim 11 , wherein the remainder of the hairpins along the inner and outer diameters of the hairpin windings are each atypical hairpins. 
     
     
       13. The electric machine of  claim 7 , wherein the hairpin windings form three electrical phases. 
     
     
       14. The electric machine of  claim 13 , wherein each electrical phase is comprised of three of the plurality of electrical paths of interconnected hairpins. 
     
     
       15. The electric machine of  claim 14 , wherein the three electrical paths of interconnected hairpins of each electrical phase are arranged in parallel relative to each other. 
     
     
       16. An electric machine comprising:
 a stator core defining fifty-four slots that are circumferentially arranged between an inner diameter and an outer diameter of the stator core, each slot having six pin positions that are arranged in a direction that extends from the inner diameter of the stator core toward the outer diameter of the stator core; and 
 hairpin windings having three electrical phases, each electrical phase having three parallel electrical paths of interconnected hairpins disposed within the slots, each of the electrical paths of interconnected hairpins having first, second, third, and fourth types of hairpins, wherein (i) each of the first type of hairpins has a first crown portion spanning eight slots and first and second opposing inwardly extending twist portions, each of the first and second twist portions spanning four and one half slots, (ii) each of the second type of hairpins has a second crown portion spanning nine slots and third and fourth opposing inwardly extending twist portions, each of the third and fourth twist portions spanning four and one half slots, (iii) each of the third type of hairpins has a third crown portion spanning ten slots and fifth and sixth opposing inwardly extending twist portions, each of the fifth and sixth twist portions spanning four and one half slots, and (iv) each of the fourth type of hairpins has a fourth crown portion spanning nine slots, a seventh inwardly extending twist portion, and an outwardly extending twist portion on an opposing side of the fourth crown portion relative to the seventh inwardly extending twist portion, each of the seventh inwardly extending twist portions and outwardly extending twist portions spanning four and one half slots. 
 
     
     
       17. The electric machine of  claim 16 , wherein a subset of hairpins forms terminal lead connections along an inner diameter or an outer diameter of the hairpin windings. 
     
     
       18. The electric machine of  claim 17 , wherein a remainder of the hairpins other than the subset of hairpins along the inner and outer diameters of the hairpin windings are the fourth type of hairpins. 
     
     
       19. The electric machine of  claim 16 , wherein a subset of hairpins disposed in a middle layer between an inner diameter and an outer diameter of the hairpin windings of each electrical phase are arranged in groups of three, (ii) each hairpin of each set of three is from a different electrical path of the three parallel electrical paths of each phase, and (ii) each set of three includes one hairpin having a crown pitch of eight, one hairpin having a crown pitch of nine, and one hairpin having a crown pitch of ten. 
     
     
       20. The electric machine of  claim 16 , wherein (i) each electrical phase has six poles and (ii) each pole is comprised of a portion of the interconnected hairpins that occupy three consecutive slots.